Bare bones straight up you have 880, How are these units equipped, becaue that can chage the point total. You could get an 1K list but it will be hard to be competative. before buying any more I would:
I would tak a long look at the codex and figure out just what you want to do with your army as well as how you normally play.
Then I would do a seach in the Ork armylist for Blood Axes and look at all the list there, plus some of the others for diversity.
Last build a few different lists on paper for 1K and 1.5K then playtest with a friend using "proxy" models you don't own.
This will save you money in the long run, help you build an army you like and be fluffy as well.
Chaos- Black Legion & Steel Brethren
W:16 D:7 L:9 W:9 D:2 L:5
Eldar Dragon Claws Corsairs
W:16 D:4 L:2
Da Skull Krushaz
W:27 D:2 L:13
W:14 D:0 L:3